Elastic Relaxation of Pre-stressed Bilayer

In recent decade, the principle of bimetal bending was exploited in the field of thin films. Rolled-up micro- to nanotubes with multiple windings were obtained with this technology as well as wrinkled nanostructures. The competition of these two morphologies is studied by simulation of elastic relaxation with the help of Structural Mechanics Module. The structure consists of first layer compressed initially and second layer without initial strain. If the difference of the initial strains of the layers is sufficiently large, bending into the tube is preferred, otherwise wrinkling is observed. For medium strain gradient, intermixing shape of tube with wrinkles is the result of elastic relaxation. Additional information and qualitative experimental comparison can be found in article P. Cendula et al, submitted (2013).